Hi,

Just want to ask about the latest DDMF Superplugin latency that I found a little strange when real-time oversampling is activated inside the plugin. The higher the oversampling, the lower the latency gets which I believe is kinda the opposite to what we all used to. If this is normal why would all other plugins do it the other way around ? Just wondering if this is a bug, I've roughly tested it but no phasing issue occurred in case the plugin mistakenly reporting the latency to the host. Maybe someone could explain why it behaves that way.

WIN11, Cubase.

Thanks.

EDIT : Added screenshots

Spoiler: Screenshots

Here's an example of Superplugin with Waves API EQ and 2500 in it.

1) No OS



2) 2x OS



3) 16x OS

 

Last edited: Dec 3, 2022

This is normal with fixed sample size latency. Because the higher the samplerate and the more samples per second, the shorter the same sample size would be in time.
Latency isn't introduced by upsampling/downsampling anyways, but by antialiasing filters and whatever else devs implement in the process.

 

Plugin latency is measured in samples. And sample lenght is smaller at higher sample rates so the latency will get lower the higher you go. Then the oversampling algorithm itself in Superplugin makes 0.1 ms of latency regardless of how many times you oversample.

In practice it depends on the plugin if it's coded to work differently at different sample rates. Pro-Q 3 in linear phase mode will report the same latency at every sample rate (not that you would need to oversample Pro-Q 3 but it's here as an example). But many plugins that introduce latency have fixed latency so the higher you go with sample rate, the lower the latency (+ 0.1 ms from the oversampling being enganed).

It's the correct behavior and exactly the same as in DDMF's Metaplugin. (the old version of Metaplugin thou has a bug that reports sometimes the wrong latency but it's easily rounded by turning Metaplugin off and back on in the insert slot)

Btw, curious to know examples of those "all other plugins that do it the other way around"...

 

This is what I meant :

Spoiler: Screenshots

1. The plugin introduces no latency at no oversampling


2) at 2x oversampling, the latency added is 1.0ms



3) and at 8x oversampling the latency increases to 3.1ms

This is what I believe every other plugin doing.

 

It's just good coding from the plugin developer. If they let the latency fixed, it would be lower the more you oversample, but CPU consumption would be much higher (the same thing when you decrease your audio interface's buffers). Like it's implemented in that Magma, the user will get a balanced performance between latency and CPU consumption.

A 3rd party oversampler like Superplugin is just a sample rate changer for the plugins you load in it. It's then up to the plugin itself how it behaves at different sample rates.

 

Why do they make such high latency plugins? if it effects the playback
i remember bouncing wavs, when using high latency fx! then resync them after
i have some old vst DLL files with no latency & run great!

 

Last edited: Dec 3, 2022

It differs from plugin to plugin. Some increase by like 1 sample. Some increase twofold. Some decrease.
The other decreasing one I can think of is FabFilter Pro-L.
As I said, latency isn't caused by upsampling/downsampling itself, but by what else is implemented. And, strictly speaking, is being set by the devs following reasoning they only know. Maybe they just want to be safe knowing audio is the same between different samplerates in realtime. Maybe they use different filters for different oversampling rates. Maybe some other antialiasing or optimization is going on.